UCC28780: How much current can draw from VDD pin during start up

Can that IC be biased separately from UCC28780 during startup? Please show the bias circuit for UCC28780 and for that IC in your design so we can make suggestions.

Please see the below diagram.

Thank you.

What is VCC circuit? Can you increase VCC circuit output current?

During start up, Vcc is limited to ~2.6V. I think the Vdd of UCC28780 can't provide the enough current.
So can you estimate how much current provide by UCC28780?

During startup total current for VDD external such VDD cap and others, can be calculated based on the datasheet equation (7) on page 17. If you provide your circuit and component values, we can help you to calculate or check your result.

Thanks for your feedback, Hong.
Based on the equation, the Vth=1.2V, Rdds=1k,Rsws=200ohm, so Isws=1mA.
Can any way to increase the Isws to ~3mA? Thank you.

That equation shows Isws possible ways. There are no other ways to get more current from UCC28780 Isws.

I found the higher voltage rating depletion mode MOSFET, higher Vgth. Maybe I can choose one with higher Vgth MOSFET.
Do TI has any suggestion?